Coronaviruses

Abstract

The coronaviruses are a group of RNA-containing agents which have been associated with respiratory illnesses in man and with a number of other diseases in laboratory and domestic animals. The name for the group was adopted to describe the characteristic fringe of crownlike projections seen around the viruses by electron microscopy; these projections are rounded, rather than sharp or pointed as is the case with the myxoviruses. Like the myxoviruses, the coronaviruses contain essential lipid and are 80–160 nm in diameter.(18) While the animal strains are readily isolated in several different systems, recovery of the human strains has posed major problems. A number of these strains have been isolated only in organ culture of the human respiratory tract. This factor has rendered difficult determination of the relationship among isolates and complicated efforts at understanding the role of these viruses in human respiratory illness. Therefore, much of the information on the epidemiology of the agents has come from serological studies.